Cleveland Police Commander Wayne Drummond said investigators were trying to confirm reports that a spilled cup of punch sparked the original argument.

He said the first 911 call came in as a report of a shot fired — which turned out not to be true — and the school was put on lockdown while several patrol cars responded within minutes.

“There were no guns, but one individual did pull out a club or a stick and one person did grab a hammer,” Drummond told NBC News.

“Officers were able to separate the combatants,” he said.

Seven adults and one teenager were arrested for aggravated rioting and prosecutors will decide whether to charge them, he said. No one was seriously injured, but there were a number of scrapes and bruises from the fisticuffs.